Adoption is the legal process through which a child joins a family different from his or her birth parents. Adoption is a permanent, lifelong commitment to a child. In CPS cases, adoption becomes an option if CPS and the child's birth parents cannot resolve issues that made it unsafe for the child to live at home. Then, CPS may ask the court to end the parents' rights to the child and place the child with another family permanently. A child can also become legally free for adoption if both birth parents agree to give up their parental rights. 

Social workers and other professionals in the field of adoption began changing terms of use to reflect what was being expressed by the parties involved. In 1979, Marietta Spencer wrote "The Terminology of Adoption" for The Child Welfare League of America (CWLA),[184] which was the basis for her later work "Constructive Adoption Terminology".[185] This influenced Pat Johnston's "Positive Adoption Language" (PAL) and "Respectful Adoption Language" (RAL).[186] The terms contained in "Positive Adoption Language" include the terms "birth mother" (to replace the terms "natural mother" and "real mother"), and "placing" (to replace the term "surrender"). These kinds of recommendations encouraged people to be more aware of their use of adoption terminology.
In Spain under Francisco Franco’s 1939–75 dictatorship the newborns of some left-wing opponents of the regime, or unmarried or poor couples, were removed from their mothers and adopted. New mothers were frequently told their babies had died suddenly after birth and the hospital had taken care of their burials, when in fact they were given or sold to another family. It is believed that up to 300,000 babies were involved. These system – which allegedly involved doctors, nurses, nuns and priests – outlived Franco’s death in 1975 and carried on as an illegal baby trafficking network until 1987 when a new law regulating adoption was introduced.[180][181]
Unlike guardianship or other systems designed for the care of the young, adoption is intended to effect a permanent change in status and as such requires societal recognition, either through legal or religious sanction. Historically, some societies have enacted specific laws governing adoption; where others have tried to achieve adoption through less formal means, notably via contracts that specified inheritance rights and parental responsibilities without an accompanying transfer of filiation. Modern systems of adoption, arising in the 20th century, tend to be governed by comprehensive statutes and regulations.
^ Carlson, V., Cicchetti, D., Barnett, D., & Braunwald, K. (1995). Finding order in disorganization: Lessons from research on maltreated infants' attachments to their caregivers. In D. Cicchetti & V. Carlson (Eds), Child Maltreatment: Theory and research on the causes and consequences of child abuse and neglect (pp. 135–157). NY: Cambridge University Press.
As the idea of institutional care gained acceptance, formal rules appeared about how to place children into families: boys could become apprenticed to an artisan and girls might be married off under the institution's authority.[19] Institutions informally adopted out children as well, a mechanism treated as a way to obtain cheap labor, demonstrated by the fact that when the adopted died, their bodies were returned by the family to the institution for burial.[20]
Ad hoc studies, performed in the U.S., however, suggest that between 10 and 25 percent of adoptions through the child welfare system (e.g., excluding babies adopted from other countries or stepparents adopting their stepchildren) disrupt before they are legally finalized and from 1 to 10 percent are dissolved after legal finalization. The wide range of values reflects the paucity of information on the subject and demographic factors such as age; it is known that teenagers are more prone to having their adoptions disrupted than young children.[91]
In another study that compared mothers who released their children to those who raised them, mothers who released their children were more likely to delay their next pregnancy, to delay marriage, and to complete job training. However, both groups reached lower levels of education than their peers who were never pregnant.[124] Another study found similar consequences for choosing to release a child for adoption. Adolescent mothers who released their children were more likely to reach a higher level of education and to be employed than those who kept their children. They also waited longer before having their next child.[122] Most of the research that exists on adoption effects on the birth parents was conducted with samples of adolescents, or with women who were adolescents when carrying their babies—little data exists for birth parents from other populations. Furthermore, there is a lack of longitudinal data that may elucidate long-term social and psychological consequences for birth parents who choose to place their children for adoption.

Identity is defined both by what one is and what one is not. Adoptees born into one family lose an identity and then borrow one from the adopting family. The formation of identity is a complicated process and there are many factors that affect its outcome. From a perspective of looking at issues in adoption circumstances, the people involved and affected by adoption (the biological parent, the adoptive parent and the adoptee) can be known as the "triad members and state". Adoption may threaten triad members' sense of identity. Triad members often express feelings related to confused identity and identity crises because of differences between the triad relationships. Adoption, for some, precludes a complete or integrated sense of self. Triad members may experience themselves as incomplete, deficient, or unfinished. They state that they lack feelings of well-being, integration, or solidity associated with a fully developed identity.[129]
Psychologists' findings regarding the importance of early mother-infant bonding created some concern about whether parents who adopt older infants or toddlers after birth have missed some crucial period for the child's development. However, research on The Mental and Social Life of Babies suggested that the "parent-infant system," rather than a bond between biologically related individuals, is an evolved fit between innate behavior patterns of all human infants and equally evolved responses of human adults to those infant behaviors. Thus nature "ensures some initial flexibility with respect to the particular adults who take on the parental role."[96]